1. Field of the Disclosure
This disclosure relates generally to information handling systems and devices, and more particularly to hybrid storage arrays.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option is an information handling system. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes. Because technology and information handling needs and requirements can vary between different applications, information handling systems can also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information can be processed, stored, or communicated. These variations allow information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems can include a variety of hardware and software components that can be configured to process, store, and communicate information and can include one or more computer systems, data storage systems, and networking systems.
One type of information handling system is a storage array. A storage array typically includes multiple disk drives or similar persistent, inexpensive storage units. A storage array can allow large amounts of data to be stored in an efficient manner while providing redundancy to promote reliability such as Redundant Array of Inexpensive Disks (RAID) functionality.
In addition to the disk drives or other persistent storage units, a storage array commonly also includes one or more array controllers (typically taking the physical form of one or more integrated circuits or circuit boards), and interface circuits to connect the storage array to an external host. The host may be a personal computer, a network server or some other information handling system. The controller includes one or more processors or similar hardwired logic that causes the storage array to read or write data to or from its persistent storage in response to requests received from the host. The controller also commonly includes memory that acts as a buffer or temporary storage for data being transferred to and from persistent storage.
Hybrid-based storage solutions combine multiple storage technologies, such as Solid State Drives (SSDs) and Hard Disk Drives (HDDs) in the same storage array. Hybrid storage arrays are a particularly attractive solution for large volume applications such as data centers and cloud computing where high performance and low cost are each of importance. These high performance hybrid arrays can combine intelligent caching software with low cost HDDs (such as Serial ATA (SATA) drives or faster Small Computer System Interface (SCSI) drives), and/or high-performance energy-efficient SSDs. The hybrid approach combines the scalability and relative affordability of HDD technology with the low-latency I/O performance and energy efficiency of SSDs.
Hybrid storage arrays are typically managed by a cache-pool-aware storage controller which uses various techniques to determine how to most efficiently provision the data between the HDD and SSD devices. For example, write data blocks may be addressed by an application software program to a primary rotating medium such as the HDDs. Intelligent SSD caching software analyzes patterns in these application I/O requests and builds access tables. The caching software uses these access tables to move the more frequently accessed data blocks from the HDD to the SSD tier so that faster retrieval is possible during future requests for the same data blocks. The intelligent caching software can also transparently execute writes directly to the low latency SSD media so that high frequency writes can be quickly acknowledged back to the application. Data written this way to the SDDs is then pushed as a background task to the HDDs when access to it becomes less frequent.
In addition, these hybrid storage arrays can also provide other services such as RAID, load balancing, encryption, and management functions while further isolating the application from the underlying hardware.